Knowledge of glasses industry
Knowledge of glasses industry
1) The myopia lens is a concave lens, which is thin in the middle (cannot be thinner than 1.0mm). The thicker the edge is, the higher the degree is. The thicker the edge of the lens is, the smaller the object is. The thicker the center is, the thicker the lens is (see the link below). The myopic lens moves the focus of the myopic eye backward and lands on the retina to obtain a clear image. Hyperopia/presbyopia lenses are convex lenses with thick middle and thin edge. The higher the degree, the thicker the middle. The hyperopia lens moves the focus forward and places the hyperopia focus on the retina to get a clear image. The smaller the diameter of the hyperopia lens blank, the thinner it is. Look at the objects getting bigger.
2) Hyperopia/presbyopia or flat light are not suitable for half frame glasses because the edges are too thin. They are very easy to collapse and are not durable. (It is OK to have a high positive degree and a small center shift. You can select half the box because the edge is not thin.). No frame is even less recommended.
3) The mirror frame for multi focus selection needs to be stable and not loose. The best is full frame, followed by half frame. No frame is suitable. Try to choose S-shaped nose support, which is used to adjust the pupil height and lens eye distance after processing. Neither U-shaped nor one type of nose support is suitable, and the one-piece nose support made of plates is not suitable. The position of pile head shall not be too thick, so that the rake angle can be adjusted after processing. The thick pile head and double pile head are not recommended. The shape of the lens close to the nose cannot be selected as the pilot's style, and enough access areas must be reserved. The frame height cannot be too small, nor is it recommended to be too large. The best frame height of short channel is between 26-28, and it is ideal to be within 30. 32 or so. The higher the frame height, the better. The lens frame shall be selected so that the eyes are in the middle of the horizontal direction as far as possible, the pupil height is above 1/2 of the frame height, and the lower eyelid basically coincides with the midline, which is ideal. The nose rest can be adjusted.
1) The myopia lens is a concave lens, which is thin in the middle (cannot be thinner than 1.0mm). The thicker the edge is, the higher the degree is. The thicker the edge of the lens is, the smaller the object is. The thicker the center is, the thicker the lens is (see the link below). The myopic lens moves the focus of the myopic eye backward and lands on the retina to obtain a clear image. Hyperopia/presbyopia lenses are convex lenses with thick middle and thin edge. The higher the degree, the thicker the middle. The hyperopia lens moves the focus forward and places the hyperopia focus on the retina to get a clear image. The smaller the diameter of the hyperopia lens blank, the thinner it is. Look at the objects getting bigger.
2) Hyperopia/presbyopia or flat light are not suitable for half frame glasses because the edges are too thin. They are very easy to collapse and are not durable. (It is OK to have a high positive degree and a small center shift. You can select half the box because the edge is not thin.). No frame is even less recommended.
3) The mirror frame for multi focus selection needs to be stable and not loose. The best is full frame, followed by half frame. No frame is suitable. Try to choose S-shaped nose support, which is used to adjust the pupil height and lens eye distance after processing. Neither U-shaped nor one type of nose support is suitable, and the one-piece nose support made of plates is not suitable. The position of pile head shall not be too thick, so that the rake angle can be adjusted after processing. The thick pile head and double pile head are not recommended. The shape of the lens close to the nose cannot be selected as the pilot's style, and enough access areas must be reserved. The frame height cannot be too small, nor is it recommended to be too large. The best frame height of short channel is between 26-28, and it is ideal to be within 30. 32 or so. The higher the frame height, the better. The lens frame shall be selected so that the eyes are in the middle of the horizontal direction as far as possible, the pupil height is above 1/2 of the frame height, and the lower eyelid basically coincides with the midline, which is ideal. The nose rest can be adjusted.